Yarn windup



June 4, 1963 B. E. HlLL, JR., ETAL United States This invention relatesgenerally to the production of yarn and, more particularly, toimprovements in the apparatus employed in packaging yarn.

In the textile field, it is well know that substantially cylindricalpackages of yarn, thread or the like may be built on a bobbin in atraverse winding apparatus. One suitable form of the apparatus which hasbeen developed in recent years is known as a print roll windup andincludes a cam-actuated traverse guide through which yarn passes to thesurface of a driven print roll. The print roll is in driving contactwith a bobbin or package situated on a roll which is rotatably mountedon a spring biased swing arm. Thus, the traverse pattern is laid down onthe surface of the print roll, carried on this roll for a short distanceand then deposited or printed on the package or cake. In this manner,the print roll functions not only to drive the package roll but also tomaintain constant the uncontrolled yarn length between the guide and thepackage. Where the uncontrolled yarn length is excessive, overthrownends result. For this reason the traverse guide is located as closely aspossible to the print roll. The resulting package has substantially flatends as well as a generally symmetrical appearance and is furthercharacterized by firmness, the absence of appreciable or pronouncedshoulders on the peripheral surface, the absence of over-thrown ends andby an equality of mechanical treatment of different incremental lengthsof yarn. These results may be achieved on conventional equipment as longas a maximum windup speed is not exceeded. Beyond that speed, the numberof print roll wraps is excessive and when high tensions are employed toreduce the number of wraps excessive sloughing and overthrown endsresult.

The most important objective of the present invention is to provideimprovements in a print roll windup which promote its effective andefiicient employment at high Winding speeds.

A corollary objective is to provide a print roll which retains thetraverse pattern despite a substantial increase in winding speeds.

With these and other objects in view, the print roll windup of thepresent invention is comprised of a traverse guide, a package roll and adriven print roll over which yarn travels from the guide to the packageroll. The print roll has a relatively high friction surface, withrespect to the yarn, in bands or zones located opposite the guidereversal points and a relatively low friction surface in a central zoneor band.

These and other objectives will be apparent from the followingspecification wherein reference is made to the accompanying drawing inwhich:

FIG. 1 is a side View of a print roll windup into which the improvementsof the present invention have been incorporated; and

FIG. 2 is a plan view of the print or drive roll shown in FIG. 1.

The yarn-winding apparatus chosen for purposes of illustration includesgenerally a barrel cam 10, a traverse guide 12, a driven print roll 14,and a package roll 16. Driven cam has a sinuous groove 18 in its surfaceand is mounted for rotation in spaced trunnions 20. Guide 12 rides ingroove 18 and is limited to a reciprocating linear path of travel byrails which have atent O "ice been omitted from the drawing for purposesof clarity. It should be noted that guide 12 is located as closely aspossible to the surface of drive roll 14, which is rotatable in a pairof trunnions 22. Package roll 16 is mounted for rotation on a springbiased swing arm 24 and is adapted to receive a bobbin or tube 27 onwhich a package 29 is wound.

As shown in FIG. 2, the cylindrical surface of drive roll 14 is dividedinto two outer zones or bands 26 and a central band 28. The outer zoneshave a surface finish which has a relatively high coefiicient offriction with respect to the yarn whereas the central zone 28 isprovided with a surface finish having a relatively low coefficient offriction. The high friction finishes are usually prepared by grinding,chrome-plating and then butfing the roll.

Ordinarily, the central zone 28 has a matte finish which is prepared byroughening the surface uniformly either before or after it has beenchrome plated. The roll surface is roughened by sand or Vapor blasting.

Where mentioned herein, actual friction coefiicients were obtained on aGeneral Purpose Yarn Friction Tester (Shirley Development, Ltd.) inaccordance with the test procedures described by Buckle and Pollit inthe Journal of Textile Institute, 1948, 39, T-l99. In these tests, asample of denier, 34 filament, Rotoset, Type 56 polyester, continuousfilament yarn, as manufactured by the assignee hereof, was passed in aWrap on the test roll and run at 220 yards/minute with a pretension of15 grams. The coefiicient is read directly from a scale which has 1.0 asthe upper limit and which is very compressed adjacent that limit.

In one instance, a drive roll prepared in this manner was tested andfound to have friction coefi'icients of about 0.95 in the end zones andabout 0.22 in the central zone. Using the well-known belt-frictionformula, other rolls have been tested and found to have .coefiicientsvarying from 0.8-1.0 in the end zones and from 0.2-0.4 in the centralzone. As an alternative to the metallic surface finishes, the roll maybe coated with a suitable, wear resistant, ceramic coating of aluminumoxide, chromium sesquioxide or the like. Here again, the high frictionzones may be prepared by bufling and the low friction zone by sand orvapor blasting. Although metallic or ceramic surfaces are particularlyuseful when lower denier, textile yarns are being wound, it ispracticable and sometimes preferred that the end zones be strips ofurethane rubber or the like, e.g., when higher deniers such as tire yarnare being wound.

In operation, a yarn end 30 passes through and is reciprocated rapidly:by guide 12. The path followed by the yarn as it is deposited on thedrive roll surface is as indicated by the numeral 32 in FIG. 2. Asshown, those portions of the path 32 which lie in zones 26 correspond tothe reversal points of guide 12. The high friction finish on these endzones acts to stabilize the yarn in its passage over drive roll 14 andto prevent slips or sloughs' toward the center of package 29. The use ofa relatively low friction finish on the larger central band 28 insuresagainst the development of any appreciable number of drive roll wraps.As a direct result of the banded print roll surface described herein,windups of the type which has been illustrated can be operated botheifectively and efiiciently at speeds in excess of 2000 yards perminute.

The illustrated print roll has only the three zones and is thus adaptedonly for use in the winding of a single package. If desired, the swingarm 24 can be adapted to receive a plurality of tubes 27. In this event,it would also be necessary to provide additional print roll facilitiesfor each tube, either by arranging separate rolls in tandem or byproviding alternate high and low friction finishes on an elongated roll.The integral roll could be grooved and the tandem rolls spaced tofacilitate installation of transfer tail'mechanisms. "It is apparentthat these and other changes and modifications may be made in thedisclosed yarn-winding apparatus Without departing from the spirit ofthe present invention which is, therefore, intended to be limited onlyby the scope of the appended claims.

Having thus described the invention, What is claimed as new and desiredto be secured by Letters Patent is:

1. A yarn-Winding apparatus comprising a package roll, a print rolldriving the package roll and a reciprocating traverse guide throughwhich yarn travels to the print roll, the latter having a low frictionsurface in a central zone bounded by zones having high frictionsurfaces, said high friction zones being located opposite the guidereversal points and having surface friction Vcoeificients of at least0.8, said central zone having a surface friction coefiicient of 0.2-0.4.

2. In a yarn-Winding apparatus including a reciprocating traverse guidethrough which yarn travels to a package roll, a drive roll in rollingengagement with saidpackage roll, said drive roll having at least threeseparate but ad- 4. jacent surface zones in the length thereof engagingsaid package roll, the roll surface in the central zone having arelatively low coefficient of friction with respect to said yarn, theroll surface of the outer zones being located opposite the guidereversal points and having a coefiicient of friction with respect tosaid yarn of at least 0.8, said central zone having a surface frictioncoefi'icient of 0.2-0.4. r 3. The apparatus of claim 2 wherein saiddrive roll has a metallic surface, said central zone has a matte finishand said outer zones have a highly polished finish.

4. The apparatus of claim 2 wherein said central zone has a mattefinished metallic surface and said outer zones have a rubber surface.

5. The apparatus of claim 2 wherein said drive-roll has 7 a ceramiccoating, said central Zone has a matte finish and said outer zones havea highly polished finish.

ReferencesrCited in the file of this patent UNITED STATES PATENTS2,664,249 Wright Dec. 29, 1953

1. A YARN-WINDING APPARATUS COMPRISING A PACKAGE ROLL, A PRINT ROLLDRIVING THE PACKAGE AND A RECIPROCATING TRAVERSE GUIDE THROUGH WHICHYARN TRAVELS TO THE PRINT ROLL THE LATTER HAVING A LOW FRICTION SURFACEIN A CENTRAL ZONE BOUNDED BY ZONES HAVING HIGH FRICTION SURFACES, SAIDHIGH FRICTION ZONES BEING LOCATED OPPOSITE THE GUIDE REVERSAL POINTS ANDHAVING SURFACE FRICTION COEFFICIENTS OF AT LEAST 0.8, SAID CENTRAL ZONEHAVING A SURFACE FRICTION COEFFICIENT OF 0.2-0.4.